Fix #8068: always allow removal of tram track if that generates money (#8509)

Even if you are completely broke, generating money should always
be allowed.

src/road_cmd.cpp

@@ -1109,7 +1109,8 @@ CommandCost CmdRemoveLongRoad(TileIndex start_tile, DoCommandFlag flags, uint32
 		p2 ^= IsInsideMM(p2 & 3, 1, 3) ? 3 : 0;
 	}
 
-	Money money = GetAvailableMoneyForCommand();
+	Money money_available = GetAvailableMoneyForCommand();
+	Money money_spent = 0;
 	TileIndex tile = start_tile;
 	CommandCost last_error = CMD_ERROR;
 	bool had_success = false;
@@ -1126,8 +1127,8 @@ CommandCost CmdRemoveLongRoad(TileIndex start_tile, DoCommandFlag flags, uint32
 			CommandCost ret = RemoveRoad(tile, flags & ~DC_EXEC, bits, rtt, true);
 			if (ret.Succeeded()) {
 				if (flags & DC_EXEC) {
-					money -= ret.GetCost();
-					if (money < 0) {
+					money_spent += ret.GetCost();
+					if (money_spent > 0 && money_spent > money_available) {
 						_additional_cash_required = DoCommand(start_tile, end_tile, p2, flags & ~DC_EXEC, CMD_REMOVE_LONG_ROAD).GetCost();
 						return cost;
 					}